Zika Virus

Disease Details

About Zika Virus

Zika virus is a disease that is spread to humans primarily through the bite of an infected Aedes species mosquito. About 1 in 5 people infected with Zika virus will become ill. There is currently no vaccine for Zika virus.

Symptoms

The most common symptoms of Zika are fever, rash, joint pain, or conjunctivitis (red eyes). Other common symptoms include muscle pain and headaches lasting for several days to a week. Severe disease requiring hospitalization is uncommon and deaths are rare.

Geographic Distribution

Prior to 2015, Zika virus outbreaks have occurred in areas of Africa, Southeast Asia, and the Pacific Islands. In May 2015, the Pan American Health Organization (PAHO) issued an alert regarding the first confirmed Zika virus infections in Brazil. Currently, outbreaks are occurring in many countries, however, locally transmitted Zika virus has been reported in the Commonwealth of Puerto Rico. With the recent outbreaks, the number of Zika cases among travelers visiting or returning to the United States will likely increase. These imported cases could result in local spread of the virus in some areas of the United States.

Risks to Pregnant Women

There have been reports of a serious birth defect of the brain called microcephaly (a condition in which a baby’s head is smaller than expected when compared to babies of the same sex and age) and other poor pregnancy outcomes in babies of mothers who were infected with Zika virus while pregnant. Knowledge of the link between Zika and these outcomes is evolving.

Until more is known, and out of an abundance of caution, Centers for Disease Control and Prevention (CDC) recommends special precautions for pregnant women and women trying to become pregnant:

Pregnant women in any trimester should consider postponing travel to the areas where Zika virus transmission is ongoing. Pregnant women who do travel to one of these areas should talk to their doctor or other healthcare provider first and strictly follow steps to avoid mosquito bites during the trip.

Pregnant women in any trimester should consider postponing travel to the areas where Zika virus transmission is ongoing. Pregnant women who do travel to one of these areas should talk to their doctor or other healthcare provider first and strictly follow steps to avoid mosquito bites during the trip.

Women trying to become pregnant who are thinking about becoming pregnant should consult with their healthcare provider before traveling to these areas and strictly follow steps to prevent mosquito bites during the trip.

Because specific areas where Zika virus transmission is ongoing are difficult to determine and likely to change over time, CDC will update this travel notice as information becomes available. Check the CDC travel website frequently for the most up-to-date recommendations.

Guillain-Barre Syndrome

Guillain-Barre syndrome (GBS) is a rare disorder where a person’s own immune system damages the nerve cells, causing muscle weakness and sometimes, paralysis. These symptoms can last a few weeks or several months. While most people fully recover from GBS, some people have permanent damage and in rare cases, people have died.

The Brazil Ministry of Health is currently reporting an increase in GBS cases that have occurred at the same time as their outbreak of Zika virus, and similar increases in GBS have been reported following past outbreaks of Zika in other countries. CDC will be conducting a study in Brazil beginning in late January to determine if any relationship exists between Zika virus infection and Guillain-Barre Syndrome.

Zika Virus Prevention

Zika virus can be prevented by avoiding mosquito bites. Mosquitoes that spread Zika virus, Aedes species mosquitos, bite mostly during the daytime. These same mosquitoes also spread dengue and chikungunya viruses.

When traveling to countries where Zika virus or other viruses spread by mosquitoes are found, take the following steps:

Use Insect Repellents

Always follow the label instructions when using insect repellent or sunscreen.

When used as directed, insect repellents are safe and effective for everyone, including pregnant and nursing women.

Most insect repellents can be used on children. Do not use products containing oil of lemon eucalyptus in children under the age of three years.